International publication No. 2016/133161 (hereinafter referred to as a Patent Literature 1) discloses, in order to etch an optical material layer with hard-processing property, providing a base layer between a resin layer and the optical material layer, forming an opening at the resin layer using a nanoimprint technique, etching the base layer through the opening at the resin layer, and etching the optical material layer through the opening at the base layer formed by the etching, so that a deeper recess is formed in the optical material layer.